﻿using System;
using System.Management;
using System.Security.Cryptography;
using System.Security;
using System.Collections;
using System.Text;

namespace Okra.NstdaGisTool {
    /// <summary>
    /// Generates a 16 byte Unique Identification code of a computer
    /// Example: 4876-8DB5-EE85-69D3-FE52-8CF7-395D-2EA9
    /// </summary>
    public class FingerPrint {
        private static string fingerPrint = string.Empty;
        public static string Value() {
            if (string.IsNullOrEmpty(fingerPrint)) {
                fingerPrint = GetHash("CPU >> " + cpuId() + "\nBIOS >> " + biosId() + "\nBASE >> " + baseId()
                    //+"\nDISK >> "+ diskId() + "\nVIDEO >> " + videoId() +"\nMAC >> "+ macId()
                                     );
            }
            return fingerPrint;
        }

        private static string GetHash(string s) {
            MD5 sec = new MD5CryptoServiceProvider();
            ASCIIEncoding enc = new ASCIIEncoding();
            byte[] bt = enc.GetBytes(s);
            return GetHexString(sec.ComputeHash(bt));
        }
        
        private static string GetHexString(byte[] bt) {
            string s = string.Empty;
            for (int i = 0; i < bt.Length; i++) {
                byte b = bt[i];
                int n, n1, n2;
                n = (int)b;
                n1 = n & 15;
                n2 = (n >> 4) & 15;
                if (n2 > 9)
                    s += ((char)(n2 - 10 + (int)'A')).ToString();
                else
                    s += n2.ToString();
                if (n1 > 9)
                    s += ((char)(n1 - 10 + (int)'A')).ToString();
                else
                    s += n1.ToString();
                if ((i + 1) != bt.Length && (i + 1) % 2 == 0) s += "-";
            }
            return s;
        }

        #region Original Device ID Getting Code
        //Return a hardware identifier
        private static string identifier(string wmiClass, string wmiProperty, string wmiMustBeTrue) {
            string result = "";
            System.Management.ManagementClass mc = new System.Management.ManagementClass(wmiClass);
            System.Management.ManagementObjectCollection moc = mc.GetInstances();
            foreach (System.Management.ManagementObject mo in moc) {
                if (mo[wmiMustBeTrue].ToString() == "True") {
                    //Only get the first one
                    if (result == "") {
                        try {
                            result = mo[wmiProperty].ToString();
                            break;
                        }
                        catch {
                        }
                    }
                }
            }
            return result;
        }

        //Return a hardware identifier
        private static string identifier(string wmiClass, string wmiProperty) {
            string result = "";
            System.Management.ManagementClass mc = new System.Management.ManagementClass(wmiClass);
            System.Management.ManagementObjectCollection moc = mc.GetInstances();
            foreach (System.Management.ManagementObject mo in moc) {
                //Only get the first one
                if (result == "") {
                    try {
                        result = mo[wmiProperty].ToString();
                        break;
                    }
                    catch {
                    }
                }
            }
            return result;
        }

        private static string cpuId() {
            //Uses first CPU identifier available in order of preference
            //Don't get all identifiers, as very time consuming
            string retVal = identifier("Win32_Processor", "UniqueId");
            if (retVal == "") //If no UniqueID, use ProcessorID
            {
                retVal = identifier("Win32_Processor", "ProcessorId");
                if (retVal == "") //If no ProcessorId, use Name
                {
                    retVal = identifier("Win32_Processor", "Name");
                    if (retVal == "") //If no Name, use Manufacturer
                    {
                        retVal = identifier("Win32_Processor", "Manufacturer");
                    }
                    //Add clock speed for extra security
                    retVal += identifier("Win32_Processor", "MaxClockSpeed");
                }
            }
            return retVal;
        }

        //BIOS Identifier
        private static string biosId() {
            return identifier("Win32_BIOS", "Manufacturer")
                + identifier("Win32_BIOS", "SMBIOSBIOSVersion")
                + identifier("Win32_BIOS", "IdentificationCode")
                + identifier("Win32_BIOS", "SerialNumber")
                + identifier("Win32_BIOS", "ReleaseDate")
                + identifier("Win32_BIOS", "Version");
        }

        //Main physical hard drive ID
        private static string diskId() {
            return identifier("Win32_DiskDrive", "Model")
                + identifier("Win32_DiskDrive", "Manufacturer")
                + identifier("Win32_DiskDrive", "Signature")
                + identifier("Win32_DiskDrive", "TotalHeads");
        }

        //Motherboard ID
        private static string baseId() {
            return identifier("Win32_BaseBoard", "Model")
                + identifier("Win32_BaseBoard", "Manufacturer")
                + identifier("Win32_BaseBoard", "Name")
                + identifier("Win32_BaseBoard", "SerialNumber");
        }

        //Primary video controller ID
        private static string videoId() {
            return identifier("Win32_VideoController", "DriverVersion")
                + identifier("Win32_VideoController", "Name");
        }

        //First enabled network card ID
        private static string macId() {
            return identifier("Win32_NetworkAdapterConfiguration", "MACAddress", "IPEnabled");
        }
        #endregion
    }
}
